反应详情

20 ml of 90% nitric acid is added to 100 ml of 98% sulphuric acid with stirring and cooling. To this solution is added portion-wise 6.9 g (41.1 mmol) of 2,6-dimethyl-4-hydroxy-nicotinic acid. The mixture is stirred at 80° C. for 1 hour, cooled down and added cautiously 300 g of crushed ice. The resulting suspension is filtered off. The cake is washed with water and dried. There is obtained 6.7 g (77%) of a white solid.

1. temperaturecooling
2. stirringThe mixture is stirred at 80° C. for 1 hour
3. temperaturecooled down
4. filtrationThe resulting suspension is filtered off
5. washThe cake is washed with water
6. customdried